In recent years there have been a number of commercially available picture frames and frame sections formed from extruded metal such as aluminum. These picture frames often are available in unassembled kit form. The most common technique for assembling the picture frame sections into the complete frame includes the provision of channels on the rear surface of each of the frame sections, with the channels of adjacent sections in the corners of the frame meeting in L-shaped configuration. Typically, the adjacent ends of the frame sections have been assembled, to form a corner of the frame, by placing an L-shaped bracket at each corner of the frame so that each leg of the bracket extends into the channel of one of the adjacent frame sections. Each of the bracket legs is secured to its associated framing section by suitable locking means, usually a screw which is threaded through the leg of the bracket and which is urged firmly against the rearwardly facing, inner surface of the channel formed on the rear surface of each framing member.
While the foregoing technique has been used widely, it does have some disadvantages. For example, the joint at the adjacent ends of the frame sections tend to loosen with time. This may be the result of the relatively soft character of aluminum which is used typically for the extruded frame sections. Additionally, because frames of the type described may be assembled and disassembled with relative ease, these frames often are used repeatedly to frame a number of different pictures. Because the screws which ordinarily bear firmly against the rearwardly facing surface of the aluminum channel tend to mar the channel and form depressions in the channel, the surface of the channel becomes irregular which reduces the effective holding power of the screws. This aggravates the inherent difficulty of typical prior devices which, even when unmarred by repetitive tightening of the screws, tends to make a poor and sometimes loose joint at the corners where the adjacent frame sections meet. It is among the primary objects of the invention to provide an improved arrangement for securing the adjacent ends of the frame sections together which avoids the foregoing difficulties.